# coding:UTF-8

from __future__ import division


def shuan(x, o, y):
    if o == '+':
        return x + y
    elif o == '-':
        return x - y
    elif o == '*':
        return x * y
    elif o == '/':
        return x / y
    else:
        return 'error'


x = int(input("输入第一个数："))
o = input("输入运算符：")
y = int(input("输入第二个数："))
res = shuan(x, o, y)
print (x, o, y, "=", res)
input("按任意键结束...")
